Random heat

[Micro Mudder]

Well my this last summer I helped my former teacher buy a festiva from a member and this morning on his way to teach English for UNL his heat didn't work in 0 degree weather for his whole hour and a half drive and on the way back it worked? Any one know what would cause this?

[bravekozak]

It sounds to me like a blockage came loose.

[Micro Mudder]

So would a radiator flush fix it cuz it worked the day before?

[Gomez]

Mine works great down to about 10*. This morning at -17* it didn't work at all for my entire 15 minute drive to work. Worked ok on the way home at 4*. I can't speak for anyone else but I found the limit of my car anyway. and

[Micro Mudder]

That's what I though to at first but his heater worked great with it at - 30* so would a radiator flush fix it?

[Gomez]

Oh man, I am probably not the person to ask. But if I have to venture a guess I would say sticking 'open' thermostat. Not sure on blockage though. If it worked great at -30* then I would say it is flowing pretty good, even if it is intermittent. But then a small blockage that the cold somehow busted loose may be the culprit though, like Bravekozak said. Guess it wouldn't hurt to try it.

[Micro Mudder]

Yea it thought thermostat too but wasn't sure sence it worked on his way home but a thermostat and a flush sounds like the best route

[william]

Did the blower work? A few months back my blower was doing that.
One day it would work than it wouldn't then it stopped all together.
I cleaned it and put in some brushes from a Window motor and it works now.
But when I first read this I thought may be it was froze up like to cold for the antifreeze mix but if it was ok at -30 that's probably not it.

[Gomez]

would be cheap and worth a try in my opinion

[Micro Mudder]

And I totally forgot to mention the temp on the dash was reading normal! So the t-stat is good just needs a good flush then

[Bert]

And I totally forgot to mention the temp on the dash was reading normal! So the t-stat is good just needs a good flush then

The gauge was reading normal and yet there was no heat? And presumably the blower is working.
New members and visitors on here over the years have complained that their Festy dash vents don't blow warm air! Don't overlook the potential of such a mishap.
Flushing the cooling system is not a big ordeal but trying to get 'sudden' sediment or sludge out of a heater core is not going to be easy.

[Micro Mudder]

He knows his dash vents don't blow worm air I already joked to him about that but doing a reverse heater core flush with a hose will make it a bit easier to get the gunk out